The cooling fluid circulating pump for many internal combustion engines has a single seal disposed between two chambers of the pump housing with one chamber typically being a pressurized fluid chamber and the other chamber being at atmospheric pressure. The seal is provided between the chambers to primarily prevent the loss of the fluid under pressure. The nature of sealing allows some fluid leakage between the sliding faces of the seal. Corrosion inhibitors present in the fluid, namely silicates, are deposited on the seal faces and result in rapid scoring of the seal faces. Therefore, premature failure of the seal often occurs due to the progressive leakage of fluid across the seal face.
It has been shown in gas pumping designs that a lubricant chamber may be provided adjacent a pump chamber. In this design, the pump chamber contains pressurized gas at a relatively constant pressure and the lubricant chamber is pressurized from an external source. Adjustments are made so that the pressure in the lubricant chamber is greater than the pressure in the pump chamber. A mechanical seal is provided to separate the lubricant chamber from the pump chamber. The addition of pressure into the lubricant chamber substantially eliminates gas loss across the mechanical seal face. Some of the problems encountered therewith is that the external pressure source adds weight and cost if used for an engine. In addition to the above problems, pressure fluctuations within the pump chamber may require subsequent pressure adjustments in the lubricant chamber. The subsequent pressure adjustments in the lubricant chamber would not be made automatically, and if not corrected in a timely manner, could allow leakage of gas from the pump chamber.
The present invention is directed to overcoming one or more of the problems as set forth above.